Who the f*** is this guy in Transformers: Age of Extinction?

It's an extra. There's actually two of them in the scene. The mistake in this scene is the wall Cade hides behind. Watch closely (even slow the vid down if you have to). He runs across firing and hides behind a whitish rectangular slab. Cut to a close-up and he's suddenly behind a brick wall that appeared out of thin air, and the rectangular slab he did hide behind can be seen in the distance over the top of the magically-appearing wall.

This is where you see the two extras. There's one with Cade behind the magical brick wall and there's another in the distance (you see him clearly moving around) near the rectangular slab Cade originally ran to.